UL 1993 CRD-2018 UL Standard for Safety Self-ballasted lamps and lamp adapters - Section Paragraph Reference SC4 1 2 C SC4 1 4 Subject Current adjustment for Type A lamp power sou.pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared by UL LLC. It is normative for the applicable ULProduct Certification Program(

2、s); however, it is currently not part of the UL Standard(s) referencedbelow.Product Category (CCN): OOLVStandard Number: UL 1993Standard Title: Standard for Self-ballasted lamps and lamp adaptersEdition Date: January 27, 2017Edition Number: 5Section / Paragraph Reference: SC4.1.2 SC4.1.4Subject: Cur

3、rent adjustment for Type A lamp power sourcesDECISION:SC4.1.2 When a test requires the device to be energized from its intended supply source, it shall beenergized from both the 60 Hz (line frequency) and 25 kHz HF (high frequency) reference ballasts in turn.The reference ballasts shall comply with

4、NEMA C82.3 and be used as the supply sources for the LEDlamp tests in this supplement, as follows:a) The reference ballast shall be initially adjusted for the voltage, current, and powercharacteristics of the target lamp in accordance with NEMA C82.3. For double-endedfluorescent lamps, these charact

5、eristics can be found in NEMA C78.81. For single-endedlamps, these characteristics can be found in NEMA C78.901.b) Once With the LED lamp is connected and energized from the reference ballast, the inputcurrent to the LED lamp and the voltage across the LED lamp are monitored. The referenceballast re

6、sistance shall be is then adjusted until one of the following occurs: so that the LEDlamp is operating at the target lamps rated current.For the purposes of this requirement, the HF reference ballast may be operated at frequencies up to 50kHz.Note 1: The adjusted power sources are not considered ref

7、erence ballasts for the purposes of NEMAC78.81.Note 2: The reference ballasts rated or typical input voltage can be found under “Reference BallastCharacteristics” on the NEMA C78.81 and NEMA C78.901 target lamp datasheets.SC4.1.3 As an alternative to the 25 kHz HF reference ballast described in Clau

8、se SC4.1.2, an electronicsinusoidal 25 50 kHz current source of sufficient current and power capacity may be used to power theLED lamp, provided that the source has the following characteristics:a) Capacity to supply at least 125% of the target lamps rated voltage at the lamps operatingcurrent;b) Ou

9、tput voltage total harmonic distortion (THD) 3% while unloaded;c) Output frequency regulation 2%; andd) Output current regulation 1%.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULThe current source shall be adjusted to either operating point

10、 specified in SC4.1.2.b.1 or SC4.1.2.b.2,whichever occurs first.SC4.1.4 In reference to Clauses SC4.1.2 and SC4.1.3, a device designed and intended to function onlyon either magnetic or electronic (high frequency) ballasts may be evaluated using only the corresponding60 Hz or 25 kHz HF reference bal

11、last if the device complies with the following when connected to thenon-intended reference ballast and tuned for the target lamp:a) It draws no more than 10% of the target lamps rated power; andb) It does not induce an unacceptable DC component on the reference ballast or the cathodetransformers.RAT

12、IONALE FOR DECISION:This decision expands prior options for the procedure for adjusting the HF power source for Type A lampsto account for lamps that are not designed to operate at the full operating voltage of their target lamps.As written, the resistance of the HF reference ballast or the current

13、control of the HF power source isadjusted until the LED lamps under test draw the operating current of the target lamps published in thecorresponding ANSI/NEMA fluorescent lamp datasheets. However, there are LED lamps that haverelatively high internal impedance and are simply not designed to operate

14、 at the target lamp operatingcurrent. With such designs, in order to reach this desired current level, the voltage across the LED lampsmay need to reach several hundred volts, exceeding the voltage ratings of the lamps internal componentsand permanently damaging these lamps beyond use.The use of a 5

15、0 kHz power source is intended to reduce the internal impedance of the lamp to allowoperation at the intended operating current point using less voltage than would be needed at 25 kHz. Inaddition, the power source adjustment stops once you either reach the target lamp operating current orthe voltage

16、 across the lamp reaches the open circuit voltage (OCV) of the reference ballast. This will allowfor the testing of Type A lamps at their worst-case thermal operating point without subjecting them toabnormally high voltages that are unlikely during commercial ballast operation.The revision to SC4.1.

17、3.b is a clarification based on the intent of the clause.Copyright 2018 UL LLCUL LLC, in performing its functions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. C

18、ertification Requirement Decisions are the opinion of UL LLC. in practically applying therequirements of the standard. They do not represent formal interpretations of the standard underAmerican National Standards Institute (ANSI) processes. UL LLC shall not be responsible to anyone forthe use of or

19、reliance upon Certification Requirement Decisions by anyone. UL LLC shall not incur anyobligation or liability for damages, including consequential damages, arising out of or in connection withthe use or reliance upon Certification Requirement Decisions. The electronic version of the CertificationRequirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 1993 -2-